YouTube has launched its long-awaited music subscription service called Music Key in beta version. The new service comes with a $7.99 price tag for an initial promotional period, with a standard rate of $9.99 per month. YouTube Music Key offers access to Google Play Music’s entire library, as well as providing ads-free music videos, background playback capabilities, and offline caching for viewing without a connection.

To kick off the service, YouTube opens with a private invite-only beta, offered just to the heaviest music consumers on the site. However, if you are desperate to try the new service, you can sign up for Google’s other music series Google Play Music commit to $10 monthly, and you get to be a YouTube Music Key subscriber as well (and yes, you get 2 months free subscription for Music Key with it).

YouTube is the No. 1 place for folks to discover new music. Also, music videos don’t air on MTV anymore, but all of the latest pop acts release their videos on YouTube. Justin Bieber launched his career on YouTube, Harlem Shake became the song of the decade here. Top 40 doesn’t define the music scene anymore. This makes YouTube new subscription service a big deal. The video-sharing website has become a one-stop website for music videos, cover songs, lyric videos, reality shows, ‘Soldier coming home’ videos and pretty much everything. YouTube knows well that the lines between music and everything else are more blurred than before.

The company is going to make most of it with this new service. “Overall, we rely on the information that we get from our partners, or from the video uploader,” explained the YouTube spokesperson Matt McLernon in an interview. “So there are very specific cases like members of the music community, say a label or a publisher, where it’s very clear that it’s music, but the thing that makes YouTube so unique in the music space is, not only is there the traditional music side that everyone knows and loves, but with 300 hours of music and video coming to YouTube every minute, and much of that being music, there’s this whole spectrum of what people call music, or consider music, or share as music.”

The strategy YouTube has adopted is feedback-based, which is a good sign. The beta version is designed to help Google define music not just by its own standards, but by the standards of using the service for listening and watching. The aim of the beta version is to attract the most dedicated YouTube music fans, who will then offer up feedback including “why isn’t channel x included,” or “why is this here when it doesn’t seem like it should be?”

“We want it to be from both sides – we rely on the information the uploader puts in their YouTube video, but we also want to be an active part in that,” McLernon stated. “This is the same concept of what we use to determine recommended or related videos. All the different signals that we’re aware of that would tell us people are playing these videos in the same way that they would play these types of music videos.”

The company’s goal is to develop the service in the same way they developed their advertising partnership program, which started as something the company chose you out to participate in. It was complete with iterated agreements, and eventually opened its doors to all YouTube creators and uploaders to opt into.

Music downloads on iTunes are not selling the way they used to, CDs have become almost non-existent in stores, and streaming music sales keep rising. Matt admits that based on how well the beta version is received by the early users, it’s definitely possible that we’ll see the model applied in one way or another to other categories within the streaming video site too. However, Google has a big task ahead to figure out how they want to proceed with the Music Key.